Method and apparatus for forming small boats



March 27,1945. SHERMAN 2,372,521

METHOD AND APPARATUS FOR FORMING SMALL BOATS Filed March 6, 1942 H4 WV 6. SHEEN/m4 Patented Mar. 27, 1945 SMALL BOATS Alvin G. Sherman, Grosse Pointe, Mich, assignor to Globe American a corporation nporation, Kokomo, 'Ind.,

Application March 6, 1942, Serial No. 433,548

11 Claims.

This invention relates to a method andapparatus for forming small boats. The invention is particularly adapted to the manufacture ofboats having a sheet metal hull, such as arecommonly used for life boats on cargo vessels.

One object of the inventionis to providea method and apparatus by means of which the hulls of such small boats may be expeditiously and-economically formed in quantity production. To this end the method of the invention includes the shaping of a keel and gunwales and the joining of the same to form a unitary structure; Said structure is then placed in inverted position on a skeleton form whose outer dimensions conform to the desired inner shape of the sheet metal shell motor" sling and motor therein. l

/ Referring nowto Fig. 1 of the drawin there is shown therein a partially completed boat having a keel l0 and gunwales H- The keel I0 is preferably formed ofv a single flat steel bar and is curved ateach end to provide a stern post l2 and a stem post IS. .The gunwales are formed of steel inwardly fianged'as best seen'in Figs. 2 and 5 to provide an L-shaped'cross section. As the boat showing the position of. the

. firststep in the method of the invention, the keel and gunwales are shaped andare secured toor hull and the hull plates or sheets are then secured. to the keel and gunwales and to each other while in contact with the form, The shell plates may be pre-shaped to the approximate curvature,

desired but the final shape is determined by the outer shape of the form. The plates may be secured by riveting or by other suitable means. If riveted it is not necessary thatall of the rivets be driven while the hull is on the form. It is only necessary to set enough rivets to retain the hull in the desired shape. Thereafter the hull may be removed from the form and the remaining rivets may be set inplace at any desirable point in the production line.

The apparatus of the invention comprises the,

form and the several features thereof by means of which the keel and gunwale structure are held in proper position for shaping the shell. The fact that the form is of skeleton construction is important in permitting access to both sides of the shell for driving rivets.

Another feature of the apparatus of the invention resides in the provision of means as a part of the form whereby portions thereof may be retracted to permit the keel and gunwale structure to be readilyplaced in position on the form and removed therefrom.

' Another feature of the invention resides in the provision in the apparatus of means for locating a motor sling or bed and holding the same in proper position relative to the hull so that it;

may be secured thereto at the same time as the shell plates.

' Other objects and features of the invention will Fig.3 is an 'elevational'view ofone section of the form. Fig. 4 is an enlarged elevational view of a member of the form showing the provision of means for locating the motor sling. Fig. .5 is

a vertical sectional view of a partially completed.

gether as shown in Fig.1 as unitary structure. Said structure is then placedinan inverted position on the form now to be described.

' .The form inoludesa series of latera1 frames l4, one of which is shownsin detailin Figs. 2 and 3. Each of said frames is provided-with a pair of posts |5 which are preferably solidly set in a concrete floor I611. The posts [5 have secured thereto a template I6, the outer edge ll of which is shaped to conform to the desired inner curvature of the shell of the boat at the position of the individual frame}: Ineach' of: the templates l8 there is provided a series of grooves adapted to receive a plurality oflongitudinal members or ribs I8 which extend. substantially the full" length of the form and which are shaped to the desired inner'form of theshell. The uppermost of the longitudinalv members indicated by reference numberzlQ, preferably in the-form of a T-bar, see upper central portion of Fig. 2 and top of Fig. 3, and is adapted'to receive and support the keel l0. At each end of the form there is provided aZ-bar 20, see opposite ends of Fig. 1, securely fastened to the, floor Ilia and provided with suitable openings to receive the stem and stem posts l3andl2.

Each of the templates |6 is provided with a movabler'portion or plate 2| pivotally mounted on apivot pin 22. Each of said portions 2|has secured thereto a yoke 23 slidably guidin'g'a pin 24 transversely-of portion 2|. Within the yoke 23 there is provided a compression spring 25 engaging a transverse pin 26 carried by the locking pin 24. The spring 25 thus normallyholds the pin.24 in the position shown in Fig. 3, in which position said pin may engage an openin 21 in thetemplate l6. By means of this construction the member 2| may be held in the position shown at the left in Fig. 2, in which position it engages the'inner face ofthe flange of'the gunwale II and the outer edge thereof continues the curva ture of the outer edgeof the template l6. To place the plate 2| in the position shown at the right of Fig. 2, the pin 24 may be withdrawn by hand and the-plate 2| may be. movedabout its pivot pin 22. In this position the plate 2| is clear of the gunwale so that the heel and gunwale structure may be easily placed iii-position. When said structure is so placed, the plates 2| may be flange and to locate the same accurately with respect to the form.

For clamping the keel and gunwale structure 2 in place, there is provided on each of the frames M a pair of clamp members 29 pivotally mounted on yokes 30 secured to the posts l5. Each of said clamp members is provided with a handle 3| and a tension spring 32, the opposite end of which is secured to a hook 33 carried by the post l5. In the idle position of the clamp member shown at the right in Fig. 2, the spring 32 holds the same against the post l5. When said member is drawn outwardly by means of the handle 3|, the spring 32 passes over'the pivot point of the clamp member and thereafter holds said member in engagement with the gunwale II as shown at the left of Fig. 2. The several springs 32 thus clamp the gunwale securely to the form.

To retain the keel against undesired lateral movement, there are provided a series of pins 34 which are vertically slidable in the longitudinal member I9 and in yokes 35 secured to the. undersurface of said longitudinal member. Compression springs 36 surround the pins 34 within the yokes 35 andabut against lateral pins 31 carried by the pins 34. The springs 35 thus normally hold the pins 34 in the position shown in the drawing but said pins may be pressed downwardly within the confines. of the form and may be held in their downward position by the shell of the boat when said shell has been put in place. The pins 34 thus holdthe keel against lateral movement until a number of shell plates have been put in place sufficient in themselves to prevent said lateral movement of the keel.

Continuing now the description of the method of the invention, the keel and gunwale structure is placed'in position on the form with the stem and stem posts engaging openings in the Z-bars 20 and the keel resting on the longitudinal mem-.

ber IS. The plates 2| are moved into their operative position and locked by. means of the pins 24. The inside flange of the gunwale nests at 28 in plate 2|. The clamps 29. are raised to engagethe gunwales and clamp them between members 2| and clamps 29 and to hold the keel and gunwale structure rigidly in proper position. The shell plates 38, see Fig. 1, are then secured to the keel and nwales and to each other. Preferably said plates are placed diagonally as shown in Fig. 1 and the center plates are first placed in position.

motor 42. Preferably the angle members 40 are designed to fit closely against the inner surface of theshell of the boat.

To provide for accurate placement of the angle members 40 the longitudinal members N3 of the form are constructed as. shown in Fig. 4. Each of said members i broken at the position of the angle 40 and the portions ofsaid members are secured to a connecting fitting 43 having a recess 44 adapted to receive the flange of the angle 40. Said recess is extended laterally and so shaped that the outer surface of the angle 40 is substantially flush with the outer surface of the member |8 so that the angle 40 is entirely within the confines of the form. In the use of this construction the angles 40 are placed in position on the form before the keel and gunwale structure are placed thereon. Said angles are thus accurately located with respect to said boat framestructure and may be secured thereto at the same time as the shell plates 38. When the boat has been removed from the form and returned to the normal upright position, the angles 40 are ready to receive the motor base member 4|.

The plates l6 and longitudinal members l8 and member |9 form a rigid structure on which the plates 38 may rest during the riveting operation.

The skeleton form of the structure permits access to a large percentage of the interior surface of the plates 38 so that no difiiculty is encountered base as shown in Fig. 5. Said base comprises a, sling consisting of a pair of angle members 40.

located as shown in Fig. 1 andeach having its upper ends secured to the gunwales II. In the finished boat longitudinal members 4| extend between the angle members 40 and. support the From the foregoing description it will be apparent that the invention provides a method and means for rapidly and accurately shaping the hull of a sheet metal boat. The method of the invention has been described and a preferred form of apparatus for carrying out the method has been illustrated. Variations in the details of both method and apparatus may be made by those skilled in the art without departing from the scope of the invention as defined by the appended claims.

The invention claimed is:

1. Apparatus for forming small boats having a keel and gunwales joined as a unitary structure and a sheet shell, said apparatus including a series of lateral frames each shaped to the desired cross section of said shell at a particular point,

longitudinal members inset in recesses in said frames and forming therewith a skeleton form having the desired shape of said shell in inverted position, one of said longitudinal members being adapted to support said keel, a series of vertical- 1y movable pins carried by said last mentioned longitudinal member and normally extending upwardly therefrom on opposite sides of the position of said keel to restrain the same against lateral movement, and yielding means adapted to hold said pins in their normal position but permitting the same to be moved within the confines of said form, said shell when in place holding-said pins in the last described position.

2. Apparatus for forming small boats having a keel and gunwales joined as a unitary structure and a sheet shell secured thereto, said apparatus including a skeleton form having the desired shape of said shell in-inverted position for forming the same, said form including a longitudinal supporting member for said keel, and a series of. retractible projections carried .by said member normally extending therefrom on opposite sides of the position of said keel to restrain the same against lateral movement, said pinsbeing retracted from normal keel-restraining position by said shell when formed and secured to said keel.

3.. Apparatus for forming small boats having a' keel and gunwales joined as a unitary structure and a sheet shell secured thereto,.said.apparatus including a skeleton form having the desired shapeof said shell in inverted position for formingthe same, said form including alongitudinel supporting member for said keel, a series'of vertically movable pins carried by said member and normally extending upwardly therefrom on opposite sides of the position of said keelto restrain the same against lateral movement, and yielding means adapted to hold said pins in their normal position to permit the same to be moved within the confines of said form, said shell when in place holding said pins in the last-described position.

4. Apparatus for forming small boats having inwardly flanged gunwales and a keel secured thereto as a unitary structure and having a sheet shell, said apparatus including a series of lateral frames, each shaped to the desired cross section of said boat shell at a particular point forming a skeleton form having the desired shape of said shell in inverted position, the end portions of said frames departing inwardly from the shape of the shell, and an auxiliary frame member pivvinwardly flanged gunwales and a keel secured thereto as a unitary structure and having a sheet shell, said apparatus including a series of lateral frames, each shaped to the desired cross section of said boat shell at a particular point forming a skeleton form having the desiredshape of said shell in inverted position, the end portions of said frames departing inwardly from the shape of the shell, an auxiliary frame member pivotally mounted adjacent each end of said frames adapted to be swung into and out of position to engage and conform said flanged gunwales and provide a continuation of the form to the desired cross section adjacent each end of said frames, and means for locking each of said members to its respective frame portion in outward'extended gunwale conforming position.

6. Apparatus for forming small boats having inwardly flanged gunwales and a keel secured thereto as a unitary structure and having a sheet shell, said apparatus including a, series of lateral frames, each shaped to the desired cross section of said boat shell at a particular point forming a skeleton form having the desired shape of said shell in inverted position, the end portions of said frames departing inwardly from the shape of the shell, an auxiliary frame member pivotally mounted adjacent each end of said frames adapted to be swung into and out of posi tion to engage and conform said flanged gun wales and provide a continuation of the form to the desired cross section adjacent each end of said frame, means for locking each of said members to its respective frame portion in outward extended gunwale conforming position, and a pivotally mounted latch on each of said frames adjacent each end thereof movable into external engagement with their respective gunwale for conforming'it inwardly in respect to said frame members.

7. Apparatus for forming small boats having inwardly flanged gunwales and a keel secured thereto as a unitary structure and having a sheet shell, said apparatus including a series of lateral frames, each shaped to the desired cross section of said boat shell at a particular point forming a skeleton form having the desired shape of said shell in inverted position, the end portions of said frames departing inwardly from the shape of the shell, an auxiliary frame member pivotally mounted adjacent each end of said frames adapted to be swung into and out of position to engage and conform said flanged gunwales and provide a continuation of the form to the desired cross section adjacent each end of said frames, and a pivotally mounted latch on each of said frames adjacent each end thereof movable into external engagement with its respective gunwale for conforming it inwardly in respect to said frames.

8. A method of constructing a small ribless boat having a sheet plate shell comprising the steps of shaping a keel and associated gunwales, joining the ends of said keel and gunwales together into a unitary structure conforming to the genenal contour of the boat, placing said structure in an inverted position over and about a skeleton form shaped to the desired inner dimensions of said shell, mounting a plurality of sheet plates forming said shell over said form extending from gunwale to keel, and securing the ends of each of said plates to said keel and gunwales respectively and to each other while in contact with said form, said plates acting to permanently secure and hold said gunwales in relative position to said keel and form the shell of the boat without connecting ribs.

9. 'A method of constructing a small ribless boat having a sheet plate shell comprising the steps of shaping a, keel and gunwales, securing said keel and gurmlales together in inverted position over and about a skeleton form shaped to the desired inner dimensions of said shell, and thereafter permanently securing said keel and gunwales in their respective positions by mounting a plurality of said sheet plates over said form to extend from the keel to each of the gunwales respectively, and securing the ends of each of said plates to said keel and the respective gunwales while in contact with said form to provide a permanent shell acting. to secure said keel and gunwales without connecting ribs.

10. A method of constructing a small ribless boat comprising the steps of shaping a keel and gunwales, joining their ends together to form a rigid unitary structure conforming to the shape of the boat, providing a skeleton form within said structure conforming to the shape to be given said boat and to said structure, and interconnecting said keel and gunwales intermediate their ends by sheet plates having their opposite ends secured to said keel and gunwales, respectively, said sheets plates conforming to the shape of said skeleton form to provide the outer shell of the boat and the interconnecting structure between said keel and gunwales.

11. The method of constructing a small ribless boat comprising the steps of shaping a keel and gunwales, joining the same together at opposite ends into a rigid unitary structure, providing a skeleton form shaped to the desired inner dimensions of the boat about which said structure is supported, mounting a plurality of sheet strips over said form in diagonal relation to said keel and gunwales, securing the ends -of' said strips to said keel and the respective gunwales in overlapping relation, and securing additional sheet strips in angular overlapping relation to said first-mentioned strips for providing a complete shell, and whereby said strips act to secure and provide interconnecting reinforcement between said keel and the respective gunwales.

ALVIN G. SHERMAN. 

